Customers opting to buy just the guitar bundle for Guitar Hero World Tour rather than the full band kit, are for some reason getting a little extra treat from Activision.

Although World Tour expanded Guitar Hero to the full band set-up, it's still available as a guitar bundle alone. It's also obviously cheaper than the former, so why Activision seems to be encouraging this by offering free extras is a little confusing.

Still, Activision is rewarding its Complete Guitar Game Bundle customers buying the kit before the end of December with five free downloadable tracks on both Xbox 360 and PS3.

At the moment, it seems like the offer hasn't gone live yet, with a message asking players to "come back soon to redeem your five free songs".

There's been no news as to whether the free songs are able to be chosen or are pre-selected by gamers, nor any explanation as to why this is just available for guitar bundlers.

We'll let you know when we get anymore information, and when the promotion goes live.